Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Atypical cellular disorders are commonly considered part of the gray zone linking oncology to hematology and immunology. Although these disorders are relatively uncommon, they often represent significant clinical problems, provide an opportunity to understand basic disease mechanisms, and serve as model systems for the development of novel targeted therapies. This chapter focuses on such disorders. In Section I, Dr. Arceci discusses the pathogenesis of Langerhans cell histiocytosis (LCH) in terms of the hypothesis that this disorder represents an atypical myeloproliferative syndrome. The clinical manifestations and treatment of LCH in children and adults is discussed along with possible future therapeutic approaches based upon biological considerations. In Section II, Dr. Longley considers the molecular changes in the c-Kit receptor that form the basis of mastocytosis. Based on the location and function of c-Kit mutations, he develops a paradigm for the development of specific, targeted therapies. In Section III, Dr. Emanuel provides a review of the "mixed myeloproliferative and myelodysplastic disorders," including novel therapeutic approaches based on aberrant pathogenetic mechanisms. Taken together, these chapters should provide an overview of the biological basis for these disorders, their clinical manifestations, and new therapeutic approaches.
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PMID:Atypical cellular disorders. 1244 29

An 11-year old Caucasian female with a remote history of urticaria pigmentosa presented with a neck mass. A biopsy demonstrated a large intradermal nodule composed of unusually large epithelioid mast cells, including a prominent subset with bi-lobed and multi-lobed nuclei. By immunohistochemistry, the cells expressed CD117 (C-Kit), mast cell tryptase, CD68, and CD25, and were negative for CD163, CD1a, and S-100, confirming the diagnosis of mastocytoma. Equally prominent was an admixed infiltrate of CD68 and CD163-positive xanthomatous histiocytes that included Touton-type giant cells. Eosinophils were abundant. At 7 months follow-up, there was no recurrence of the lesion following complete excision. However, given the unusual cytologic features, close clinical observation is warranted, as the long-term biologic potential of mastocytoma with this degree of cytologic atypia is uncertain. Awareness of this unusual morphologic variant is also important as the histologic features may mimic such childhood neoplasms as juvenile xanthogranuloma and Langerhans cell histiocytosis.
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PMID:Histiocyte-rich pleomorphic mastocytoma: an uncommon variant mimicking juvenile xanthogranuloma and Langerhans cell histiocytosis. 1960 70

We recently encountered a 2-year-old boy with slightly infiltrative brown papules on the face, trunk, and extremities. Stroking of one of the papules produced an urticarial wheal (positive Darier's sign). Histopathologic tests revealed a dense infiltration of mast cells containing numerous granules and showing metachromasia under Toluidine blue staining. Immunohistochemical tests revealed that these cells were positive for CD68 and for c-kit. In addition, dermal dendritic cells that were positive for S100 and CD1a immunostaining were intermingled with the mast cells. We confirmed through electron microscopy that the dermal dendritic cells that were observed adjacent to the infiltration of mast cells had Birbeck granules in their cytoplasm, namely Langerhans cells. However, because of the greater numbers of mast cells than Langerhans cells, and because of the absence of both monomorphic LC proliferation and systemic symptoms of Langerhans cell histiocytosis, the present case favors a diagnosis of cutaneous mastocytosis in a child with Langerhans cell infiltration.
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PMID:A case of cutaneous mastocytosis in a child with prominent Langerhans cell infiltration. 2073